Traditionally, the size of a foot is determined by a physical device, such as a “Brannock” device, which is common in many footwear stores. A Brannock device includes a sliding element to line up with the forward edge of a toe, where a heel of the foot is braced against an opposite end of the device. This same device can also measure foot width with a separate sliding element.
One advantage of these traditional devices is that the user, or those accompanying the user, can see the dimensions generated in real-time. These individuals can agree with the measurements, dispute them, attempt further adjustment of the sliding elements or foot position, and therefore, adjust the foot measurements.
Without a physical measuring device, traditional foot measuring involves a process of trial and error to determine an appropriate shoe size. This process involves obtaining shoes of varying sizes so that the customer can try on each shoe and determine an optimal fit. This traditional method depends on feedback from the user in reaction to different physical shoes. Such trial and error can be especially challenging with children, or those who have physical disabilities or other impairments that make it challenging to gauge accurate feedback from the user.
Furthermore, a less common method of physical size determination is the use of special shoes with the forefoot constructed from clear or transparent materials. This method allows for the toe area to be viewed through the shoe. Similarly, the goal with this method is real-time feedback for the user to gauge accurate foot size. However, the main deficiency is the requirement that all different shoe styles and sizes include clear or transparent materials.
As consumers continue to move to online shopping for shoes, there is a growing interest in alternate methods of foot-sizing that are not dependent on such traditional methods of physical devices or shoes. One alternative method includes providing directions to a user to trace an outline of a target foot on a piece of paper and choose two points on the resulting contour to generate a linear measurement. Problems with this method include demanding too much time and effort from the user, dependency on the accuracy of the traced contour, and user understanding of how to measure the resulting contour itself. Furthermore, many consumers do not wish to be bothered by this process, may draw an inaccurate outline (e.g., by drawing at an angle instead of vertical), or may incorrectly measure the traced outline (e.g., by not measuring along the major longitudinal axis of the foot).
Another alternative method includes using an application on “multi-touch” device having a relatively large screen, such as a tablet computer. These applications attempt to measure foot size by having the user place the target foot on the screen, while the tablet is situated on the ground with the screen facing up. Problems with this method include inability to measure feet that are larger than the screen, inability to capture features which are not at ground/screen level and that affect the measured maximum size (for example, a heel that juts out higher on the foot), and user sensitivity to device damage by stepping on the device.
Another alternative method includes an application that attempts to measure foot size by utilizing a camera built into the computing device. These applications may use a reference object of a known size (e.g., a coin) in the same field of view and obtain a picture of the foot along with the reference object. Problems with these applications include inaccuracy based on flawed processing techniques and algorithms, unacceptably long processing times if the image or multiple images are sent to a remote server for processing, and the lack of real-time feedback to the user.
Another class of alternative methods include applications which attempt to scan an entire foot and record 3D features of the foot, or by constructing a 3D digital model of the foot through multiple images. In addition to suffering from even longer processing times than the above methods due to the greater amount of data in a 3D calculation, there are doubts about the accuracy of the data generated given the complexity of the full-foot 3D model and reliance on in-situ consumer electronics and settings (e.g., lighting, background differences, etc.). This 3D-based method is also impractical given the limited commercially viable ways to convert a full 3D digital map of a foot to a completely custom shoe. Three-dimensional printing of shoes mapped to a custom 3D database is not yet viable as a mass-consumer option due to a number of issues, including the availability of shoe materials that are also available for 3D printing (e.g., specific materials for flexibility and durability), and the processing time needed to print an object the size of a shoe.
Therefore, a need exists in the field for a foot measuring application that can both provide real-time feedback to a user and provide an accurate determination of foot size in a timely and easy fashion.